Migraine and restless leg syndrome co-morbidity may be due to iron deficiency.

Sir,

We inspected Gupta et al.'s[1] study carefully. The authors investigated the effect of restless leg syndrome (RLS) on the formation of migraine-type headache. Our opinion is that iron deficiency may have an effect on the pathophysiology of migraine seen in RLS patients. So we recommend the readers to keep in mind that iron deficiency might have an effect on migraine formation in RLS patients.

Furthermore, when we inspected Gupta et al.'s[1] study carefully, the authors investigated the effect of RLS on the formation of migraine-type headache. They focused on the hypothesis that the frequency and duration of RLS symptoms, sleep disturbance, and increased prevalence of depression, and positive family history, all caused by RLS, contribute in the formation of migrain-type headache. These factors are likely to contribute to the formation of migraine, as mentioned in the study. However, it is a recognized fact that iron deficiency is seen in RLS patients.[23]

In the study conducted by Vuković-Cvetković et al., has stated that iron deficiency anemia is common in patients with menstrual migraine and might have a trigger effect on migraine attacks.[4] In the methodology of Gupta et al.'s study, iron deficiency was not a criteria of exclusion from the study. Our opinion is that iron deficiency may have an effect on the pathophysiology of migraine seen in RLS patients. So we recommend the readers to keep in mind that iron deficiency might have an effect on migraine formation in RLS patients.